1 files changed, 23 insertions, 0 deletions

diff --git a/src/lib/libcrypto/asn1/d2i_pr.c b/src/lib/libcrypto/asn1/d2i_pr.c
index f3d1aa6240..c92b8325d8 100644
--- a/src/lib/libcrypto/asn1/d2i_pr.c
+++ b/src/lib/libcrypto/asn1/d2i_pr.c
@@ -112,3 +112,26 @@ err:
         return(NULL);
         }
 
+/* This works like d2i_PrivateKey() except it automatically works out the type */
+
+EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, unsigned char **pp,
+             long length)
+{
+        STACK_OF(ASN1_TYPE) *inkey;
+        unsigned char *p;
+        int keytype;
+        p = *pp;
+        /* Dirty trick: read in the ASN1 data into a STACK_OF(ASN1_TYPE):
+         * by analyzing it we can determine the passed structure: this
+         * assumes the input is surrounded by an ASN1 SEQUENCE.
+         */
+        inkey = d2i_ASN1_SET_OF_ASN1_TYPE(NULL, &p, length, d2i_ASN1_TYPE, 
+                        ASN1_TYPE_free, V_ASN1_SEQUENCE, V_ASN1_UNIVERSAL);
+        /* Since we only need to discern "traditional format" RSA and DSA
+         * keys we can just count the elements.
+         */
+        if(sk_ASN1_TYPE_num(inkey) == 6) keytype = EVP_PKEY_DSA;
+        else keytype = EVP_PKEY_RSA;
+        sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
+        return d2i_PrivateKey(keytype, a, pp, length);
+}